Nearly all our cats have been strays that just showed up and for the most part they did get along. Not always friends but tolerant. They all seem to actually like the dog. With the exception of Ginger, who we sadly lost to old age last week at age 20.5. Ginge died at home but that's another story. Anyway, Ginger was extremely intolerant of every cat we brought in but one would turn on her and beat her up. So I would say there's no guarantee it will work but in our case it did work far more often than it didn't.

We did take in one lovely orange male cat who seemed to get along quite well with our three, even Ginger. It was warm enough we kept him in the garage at first, even though he had been freely interacting with ours outside. Poor Murphy, it turned out he had the wet form of FIP and we euthanized him a week after live trapping him. Of course then our concern was the other cats we had but all three are ok and still ok years after exposure to Murphy.

One thing I do suggest is that you attempt to find out if the kitten is owned by people nearby. Scan him/her for a chip, put up Found posters, check out Lost ads. If he's that friendly already chances are there is a loving owner bereft at his escape.